The present invention relates to communications systems, and more particularly, to system and methods for home network communications.
Home networking is a key technology for the evolving home infotainment market, and is expected to itself become a large market over the next decade. Home networks will connect among computing devices (personal computers, palm computers, network computers, etc.), entertainment devices (TV, VCR, DVD player, video camera, audio systems, etc.), I/O devices (printer, scanner, head-sets, keyboards, remote controls, mouse, loud-speakers, etc.), home appliances, and modems (such as cable modems, DSL modems, and PSTN modems) for connecting the home network to external networks including the Internet. The home network will enable a wide range of application such as internet sharing, peripheral sharing, file and application sharing, and home automation. The home network will distribute the computation power of the computer from the study room to the living rooms.
Home networking solutions over existing telephone wiring (e.g., HomePNA) generally allow ordinary voice telephone calls to be carried over the wire, while at the same time providing up to several megabits of data throughput. Because the existing telephony wiring is already in place, these solutions provide an extremely easy and cost-effective way to create a data network in the home. Some solutions require the installing of a gateway where the Public Service Telephone Network (PSTN) interfaces with the wiring in the house. This gateway can also serve as a Voice-over-IP (VoIP) telephony gateway.
Another class of proposed home networking uses the normal AC electrical power wiring in the home for data transmission. Electrical power wiring has been used in the past for low bit-rate data applications such as home automation. Technologies for achieving multi megabit throughput on existing residential electrical wiring are under investigation in the industry. However, this approach has significant challenges, given that electrical wiring is not designed for data transmission. Also, a privacy concern exists where multiple homes are generally served off the same electrical transformer, requiring appropriate encryption to be deployed. Because the electrical wiring is the most ubiquitous in the home and because virtually every digital device in the home connects to the electrical wiring, the use of existing electrical wiring is an attractive way to create a data network in the home.
Wireless technologies, such as short-range wireless (e.g., Bluetooth) and medium range wireless (e.g., HomeRF and IEEE 802.11), are expected to provide several megabits of throughput, and are also proposed as a home network solution. However, their effectiveness can vary, depending on the size of the house, the proximity of other wireless networks, and other sources of noise.
By way of further background, the IEEE 1394 (i.LINK) standard defines a wired serial interface among digital devices. This inexpensive, easy-to-use and high-speed bus handles multimedia bandwidth requirements and provides a universal interface for a variety of devices. By allowing seamless data exchange between devices such as workstations, personal computers and digital televisions, VCRs, camcorders and set-top boxes, it enables a new generation of computers and consumer electronic devices to operate in a common environment. Originally developed as an interface to replace SCSI, IEEE 1394 offers bi-directionality, high data transfer rates and isochronous data transfers. It provides “hot plug” capability i.e. the ability to connect or disconnect equipment with the power on. It also enables devices that require audio, video and control signals to be connected with a single cable. This standard, also referred to as “Fire-wire”, requires special wires. The range between two adjacent components is limited, requiring amplifiers to supply the connectivity throughout a house.
For new homes, it is anticipated that standard Category 5 Ethernet wiring can supplement twisted-pair telephone wiring. The added cost of including this extra wiring during construction is relatively low and the benefits reaped can be great, because 100BaseT and other high-speed network types work well over this cable. In existing homes, however, it can be cumbersome to install Cat5 wiring throughout the home.
Another class of existing wiring in the home is TV wiring, consisting of coaxial cables that connect an antenna or a cable TV source to cable outlets or jacks at specific points in the home. Typically, the connection points of coaxial TV wiring are implemented by passive RF splitters. The signals transmitted over the in-home TV wiring may include regular video channels, data channels for fast Internet access (using e.g., DOCSIS cable modem), voice channels for telephony over cable, pay-per-view, control signals and more. Coaxial cable is an excellent communication medium, having a high bandwidth due to its shielding properties.
Coaxial cable TV wiring connect the incoming antenna or cable TV signals, typically via passive splitters, to the cable outlets at specific points in the home. These signals carried over the in-home coaxial TV wiring may include regular video channels, data channels for fast Internet access (using e.g., DOCSIS cable modem), voice channels for telephony over cable, pay-per-view, control signals and more.
Technically, to use the in-home TV wiring for home networking applications, one may connect standard cable modems through the cable TV (CATV) system. In this approach, data from one cable modem can be transmitted to the other cable modem via the CATV head-end. However, this configuration has the drawbacks that it loads the system, possibly beyond the typical headend system capacity, and that it introduces large delays that cannot be tolerated by at least some of the applications. Therefore, it is unlikely that cable operators will adopt this configuration.
By way of further background, conventional cable modems may be used to connect any type of home networking system to external (out of the home) networks, such as the Internet.